Thumbpiece For Modular Power-driven Knife - Patent 5400511 by Patents-337

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FIELDThis invention relates to an improved thumbpiece for a modular power-driven knife.PRIOR ARTPower-driven knives are widely used in the meat processing industry. A variety of handle shapes and sizes have been proposed to improve the operator's control of the knife during cutting operations and reduce hand fatigue resulting from grippingthe knife for extended periods of time. See, for example, U.S. Pat. Nos. 3,014,276; 4,590,676; 4,637,140; and 4,702,006. At least one of these handles, U.S. Pat. No. 4,637,140, includes a thumb rest indentation in the handle of a power-drivenknife. U.S. Pat. No. 108,141 discloses a manual knife having a cup shaped thumbpiece aligned with the central axis of the blade and extending outwardly from the upper edge of the knife blade.SUMMARY OF THE INVENTIONBroadly, the invention provides a modular power-driven knife having an improved thumbpiece. As contemplated for the present invention, the modular power-driven knife includes a handle removably attached to an annular boss extending from aheadpiece. The headpiece includes a blade housing and an annular rotary cutting blade. A drive cable extends through a bore in the handle and the annular boss to provide power to the cutting blade via gearing mounted in the headpiece. The improvedthumbpiece is mounted on the headpiece boss and is secured between the proximal end of the handle and a shoulder on the headpiece defining the forward terminus of the annular boss.The thumbpiece is rotatably adjustable with respect to its longitudinal mounting axis. The handle is also, rotatably adjustable with respect to its longitudinal axis. Thus, the thumbpiece's orientation is independent of the handle. An operatormay independently adjust the thumbpiece and handle orientation for maximum comfort and control for the particular cutting operation being performed.The thumbpiece has an annular base portion and an integral thumb support portion mounted on the base portion. The base portion

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United States Patent: 5400511


































 
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	United States Patent 
	5,400,511



 Decker
 

 
March 28, 1995




 Thumbpiece for modular power-driven knife



Abstract

An improved thumbpiece for a power-driven knife is disclosed. The one piece
     thumbpiece includes an annular base portion and a thumb support portion
     disposed vertically above the base portion. The base portion is adapted to
     be mounted on an annular boss extending from the headpiece. The thumb
     supporting portion includes a thumb contacting surface which extends
     outwardly at an acute angle with respect to the longitudinal axis of the
     base portion. The thumb contacting surface is patterned and is generally
     sinusoidal in profile and convex in cross section for supporting an
     operator's thumb in a partially flexed position along substantially the
     entire length of the thumb.


 
Inventors: 
 Decker; Richard B. (Vermilion, OH) 
 Assignee:


Bettcher Industries, Inc.
 (Biringham, 
OH)





Appl. No.:
                    
 08/096,938
  
Filed:
                      
  July 26, 1993

 Related U.S. Patent Documents   
 

Application NumberFiling DatePatent NumberIssue Date
 590026Sep., 19905230154
 

 



  
Current U.S. Class:
  30/295  ; 16/430; 16/DIG.12; 30/298
  
Current International Class: 
  B26B 25/00&nbsp(20060101); B26B 027/00&nbsp()
  
Field of Search: 
  
  







 30/276,286,295,296.1,298 16/11R,114R,DIG.12
  

References Cited  [Referenced By]
U.S. Patent Documents
 
 
 
Re25947
December 1965
Bettcher

108141
October 1870
Houseman et al.

309131
December 1884
Carter

1532822
April 1925
Kemp

1784334
December 1930
Callum

2217100
October 1940
Burns

2350494
June 1944
Champlin et al.

2827657
March 1958
Bettcher

2877018
March 1959
Turner

3014276
December 1961
Prohaska

3122774
March 1964
Lamb

3197808
August 1965
Mears

3269010
August 1966
Bettcher

3605842
September 1971
Kuri

3688403
September 1972
Bettcher

3852882
December 1974
Bettcher

3971094
July 1976
Solf et al.

4050003
September 1977
Owings et al.

4102049
July 1978
Harth

4116440
September 1978
Takeshima

4142291
March 1979
Bettcher

4161051
July 1979
Brodwin

4166317
September 1979
Bettcher

4169047
October 1979
Heckman

4170063
October 1979
Bettcher

4175321
November 1979
Bettcher

4178683
December 1979
Bettcher

4186924
February 1980
Southey

4198750
April 1980
Bettcher

4236531
December 1980
McCullough

4272077
June 1981
Spivey

4363170
December 1982
McCullough

4439924
April 1984
Bettcher

4466377
August 1984
Kolb et al.

4492027
January 1985
Bettcher

4494311
January 1985
McCullough

4509261
April 1985
Bettcher

4516323
May 1985
Bettcher et al.

4575937
March 1986
McCullough

4575938
March 1986
McCullough

4590676
May 1986
Bettcher

4601102
July 1986
Phillips

4629191
December 1986
Mancuso

4637140
January 1987
Bettcher

4702006
October 1987
McCullough

4825548
May 1989
Driggers

4854046
August 1989
Decker et al.

4894915
January 1990
Decker et al.

4905374
March 1990
Schlein

4928457
May 1990
Laperle

4941232
July 1990
Decker et al.

4964192
October 1990
Marui

4969231
November 1990
Mader et al.

5031323
July 1991
Honsa et al.

5230154
July 1993
Decker et al.



 Foreign Patent Documents
 
 
 
643674
May., 1964
BE

883682
Jun., 1980
BE

611568
Jul., 1926
FR

2218975
Sep., 1974
FR



   
 Other References 

Honsa Ergonomic Technologies Inc-information sheet for Honsa Erguip. Handle (undated)..  
  Primary Examiner:  Seidel; Richard K.


  Assistant Examiner:  Payer; Hwei-Siu


  Attorney, Agent or Firm: Watts, Hoffmann, Fisher & Heinke Co.



Parent Case Text



RELATED APPLICATION


This is a continuation-in-part of Ser. No. 07/590,026, filed Sep. 28, 1990,
     and entitled "Modular Power:Driven Rotary Knife, Improved Handle and
     Method," now U.S. Pat. No. 5,230,154.

Claims  

I claim:

1.  A thumbpiece in combination with a power-driven knife, said knife comprising a headpiece and an elongated handle removably attached to said headpiece, an annular boss extending from
the headpiece, said boss having an outer peripheral surface with a plurality of spaced apart parallel grooves, said thumbpiece comprising an annular base portion and a thumb supporting portion on the base portion, said base portion having a central axis
and an inner peripheral surface with a spline parallel to the central axis and disposed diametrically opposite said thumb supporting portion axially along the inner peripheral surface, said base portion adapted to encircle said boss with said spline
engaging a selected one of said parallel grooves thereby preventing rotation of said thumbpiece with respect to said headpiece, said thumb supporting portion having a proximal and a distal end and including a patterned thumb contacting surface extending
outwardly from said proximal end of said thumb supporting portion at an acute angle with respect to the central axis of the base portion, said thumb contacting surface being generally sinusoidal along its length and concave in a direction transverse to
its length for supporting an operator's thumb in a partially flexed position along the length of said thumb during operation of said knife.


2.  The combination as set forth in claim 1 wherein said spline of said thumbpiece base portion extends a distance substantially one-half of said base portion's axial length.


3.  The combination as set forth in claim 1 wherein said acute angle of said thumbpiece thumb contacting surface is between 25 and 30 degrees.


4.  The combination as set forth in claim 1 wherein said thumbpiece base portion has a proximal and a distal end, said proximal end of said thumb supporting portion extending outwardly beyond said proximal end of said base portion and said distal
end of said thumb supporting portion extending outwardly beyond ;aid distal end of said base portion.


5.  A thumbpiece for a power-driven knife, which knife includes a driven blade supported by a headpiece and an elongated handle, said thumbpiece comprising a base portion and a thumb supporting portion disposed on said base portion, said base
portion having a longitudinal axis and including a securing means for removably securing said thumbpiece to said headpiece and preventing rotation of said thumbpiece with respect to said headpiece, said thumb supporting portion having a proximal end and
a distal end and including a patterned thumb contacting surface extending outwardly from said proximal end of said thumb supporting portion at an acute angle with respect to the longitudinal axis of said base portion, said thumb contacting surface being
generally sinusoidal along its length and concave in a direction transverse to its length, whereby an operator's thumb is maintained in a partially flexed position and is supported along the length of said thumb when the handle is gripped and the
operator's thumb is placed on said thumb contacting surface.


6.  A thumbpiece as set forth in claim 5 wherein said base portion has a proximal and a distal end, said proximal end of said thumb supporting portion extending outwardly beyond said proximal end of said base portion and said distal end of said
thumb supporting portion extending outwardly beyond said distal end of said base portion.


7.  A thumbpiece as set forth in claim 5 wherein said base portion securing means comprises an annular ring having an inner peripheral surface, a raised spline on the inner peripheral surface disposed diametrically opposite said thumb supporting
portion and extending axially of the ring, said annular ring adapted to encircle a boss extending from said headpiece and said raised spline adapted to engage a selected one Of a plurality of grooves spaced apart on an outer periphery of said boss
thereby preventing rotation of said thumbpiece with respect to said headpiece.


8.  A thumbpiece as set forth in claim 7 wherein said spline extends a distance substantially one-half of said base portion's axial length.


9.  A thumbpiece as set forth in claim 5 wherein said acute angle is between 25 and 30 degrees.


10.  A thumbpiece as set forth in claim 5 wherein said sinusoidal thumb contacting surface when viewed along its length includes a central concave portion, a first convex portion adjacent said proximal end of said thumb supporting portion and a
second convex portion adjacent said distal end of said thumb supporting portion.


11.  A power-driven knife having a headpiece for supporting an annular rotary blade, an elongated handle removably attached to said headpiece and a thumbpiece comprising a base adapted to be secured between said headpiece and said handle and a
thumb support portion including a thumb contacting surface that is sinusoidal along its profile and concave in a direction transverse to its profile, said thumb support portion extending from the base and said thumb contacting surface located outwardly
from the handle and extending at an acute angle to the direction of elongation of the handle.


12.  A power-driven knife as set forth in claim 11 wherein said base of said thumbpiece includes a ring constructed to encircle a portion of said knife and an engagement member which cooperates with an engagement member on said knife to prevent
rotation relative to said headpiece.


13.  A power-driven knife as set forth in claim 11 wherein the acute angle of the thumbpiece thumb contacting surface is between 25 and 30 degrees.


14.  A power-driven knife as set forth in claim 11 wherein said thumbpiece thumb contacting surface includes a central concave surface region, a convex surface region near a proximal end of the thumb contacting surface and a second convex surface
region near a distal end of the thumb contacting surface.


15.  A thumb support surface of a power-driven knife, which knife includes a driven blade supported by an elongated handle having a central axis, said thumb support surface located outwardly of said handle and extending along a longitudinal axis
that forms an acute angle with said handle central axis, the surface being generally sinusoidal along the longitudinal axis and concave transverse to the longitudinal axis whereby an operator's thumb is maintained in a partially flexed position and is
supported along the length of said thumb when the handle is gripped and the operator's thumb is placed on said surface.


16.  The thumb support surface of claim 15 wherein said acute angle is between 25 and 30 degrees.  Description  

FIELD


This invention relates to an improved thumbpiece for a modular power-driven knife.


PRIOR ART


Power-driven knives are widely used in the meat processing industry.  A variety of handle shapes and sizes have been proposed to improve the operator's control of the knife during cutting operations and reduce hand fatigue resulting from gripping
the knife for extended periods of time.  See, for example, U.S.  Pat.  Nos.  3,014,276; 4,590,676; 4,637,140; and 4,702,006.  At least one of these handles, U.S.  Pat.  No. 4,637,140, includes a thumb rest indentation in the handle of a power-driven
knife.  U.S.  Pat.  No. 108,141 discloses a manual knife having a cup shaped thumbpiece aligned with the central axis of the blade and extending outwardly from the upper edge of the knife blade.


SUMMARY OF THE INVENTION


Broadly, the invention provides a modular power-driven knife having an improved thumbpiece.  As contemplated for the present invention, the modular power-driven knife includes a handle removably attached to an annular boss extending from a
headpiece.  The headpiece includes a blade housing and an annular rotary cutting blade.  A drive cable extends through a bore in the handle and the annular boss to provide power to the cutting blade via gearing mounted in the headpiece.  The improved
thumbpiece is mounted on the headpiece boss and is secured between the proximal end of the handle and a shoulder on the headpiece defining the forward terminus of the annular boss.


The thumbpiece is rotatably adjustable with respect to its longitudinal mounting axis.  The handle is also, rotatably adjustable with respect to its longitudinal axis.  Thus, the thumbpiece's orientation is independent of the handle.  An operator
may independently adjust the thumbpiece and handle orientation for maximum comfort and control for the particular cutting operation being performed.


The thumbpiece has an annular base portion and an integral thumb support portion mounted on the base portion.  The base portion includes an axially extending spline on its inner periphery.  The spline interfits with any of a plurality of grooves
on the outer periphery of the headpiece boss thereby providing the operator a choice of orientations about the longitudinal mounting axis of the thumbpiece.


As seen in side elevation, with the thumb support portion directly above the annular base portion, the thumb support portion is generally triangular in shape with the longest leg of the triangle being the thumb contacting surface.  The thumb
contacting surface of the thumb support portion extends outwardly at an acute angle with respect to the central longitudinal axis of the base portion.  The acute angle is of sufficient magnitude to alleviate the problem of "lateral pinch" which occurs
when the thumb and forefinger of the hand are too close together when a handle is gripped.  The thumb contacting surface is generally sinusoidal in profile and is patterned to reduce the likelihood of thumb slippage.  The sinusoidal profile of the thumb
supporting surface includes a convex portion at its proximal end, followed by a concave portion, terminating at its distal end with a convex portion.  The sinusoidal profile of the thumb contacting surface provides support along the entire length of the
operator's thumb thereby reducing hand fatigue while simultaneously providing improved control when the blade is moved along a cutting path.  When viewed in cross section, the thumb contacting surface is concave or inwardly dished to provide lateral
support to the thumb and reduce the possibility of the thumb slipping off the thumbpiece during operation of the knife.


The thumbpiece in use is positioned to locate the operator's thumb laterally of the handle centerline, which provides greater leverage to be applied by the thumb to the blade.  Through adjustment of the position of the thumbpiece about the
longitudinal axis of the base portion, the leverage provided by the thumb may be advantageously directed relative to the direction of cutting.


The primary object of this invention is to provide an improved thumbpiece for a power-driven knife that reduces hand fatigue resulting from gripping the knife handle over substantial periods of time.  A further object of this invention is to
provide a thumbpiece that supports the entire length of the thumb both longitudinally and laterally.  Another object of this invention is to improve operator control of the knife by utilizing the leverage of the thumb when extended away from the
longitudinal axis of the handle.  Yet another object of this invention is to reduce "lateral pinch." Still another object of this invention is to provide a thumbpiece that reduces the likelihood of thumb slippage during operation of the knife.


The above and other features of the invention will become better understood from the detailed description that follows, when considered in connection with the accompanying drawings. 

BRIEF DESCRIPTION OF THE DRAWINGS


FIG. 1 is a top plan view of a modular power-driven knife including a thumbpiece constructed in accordance with the present invention;


FIG. 2 is an exploded view of the modular power-driven knife of FIG. 1; and


FIG. 3 is a longitudinal sectional view of the thumbpiece of FIG. 1. 

DESCRIPTION OF THE PREFERRED EMBODIMENT


With reference to the drawings, FIGS. 1 and 2 show a power-driven modular knife 200 that includes a headpiece 202, a handle 204, a blade housing 206, an improved thumbpiece 208 and a tubular connector insert 210.  An annular rotary blade (not
shown) is mounted in the blade housing 206 and is powered by a drive cable 212 that extends through a handle bore 214 and co-acts with gears (not shown) mounted in the headpiece 202.  A headpiece extension 216 includes an annular boss 218 and a boss
shoulder 220.  The boss 218 has a central passageway internally threaded 222 to receive corresponding threads 224 on the tubular connector insert 210 to rotatably secure the handle 204 to the headpiece extension 216 in the manner disclosed in Applicant's
co-pending application Ser.  No. 07/590,026, filed Sep. 28, 1990, issued Jul.  27, 1993 as U.S.  Pat.  No. 5,230,154, and entitled Modular Power-Driven Rotary Knife, Improved Handle and Method, which is hereby incorporated in its entirety by reference.


The construction of the thumbpiece 208 is best shown in FIGS. 2-3.  It is a unitary piece having an annular base or mounting portion 230 and a thumb support portion 232 mounted on the base portion 230 and extending generally in the direction of a
longitudinal central axis A-A of the annular base portion.  The inner peripheral surface of the base portion 230 includes a raised axially extending spline or key 234.  The spline 234 is parallel with the longitudinal axis A--A of the base portion.  The
spline 234 is diametrically opposite of the thumb support portion 232 and is adjacent an end 236 of the base portion 230.  The base portion 230 has an axial length C (shown in FIG. 3) equal to the distance between the boss shoulder 220 and an end 238 of
the handle 204 so that when it is mounted on the boss 218 it encircles the boss and is confined axially between the boss shoulder 220 and the handle end 238, as shown in FIG. 1.  The length of the spline 234 is approximate one-half the axial length C
(shown in FIG. 3) of the base portion 230.


As can best be seen in FIG. 2, the spline 234 is receivable in any one of several (for example, five) grooves 240 in the outer periphery of the boss 218.  The peripherally spaced grooves 240 permit the thumbpiece 208 to be located at different
positions about the longitudinal axis of the handle 204 to accommodate different thumb positions.  When the base portion 230 is mounted on the boss 218, the thumb support portion 232 is offset from the handle centerline.  The thumbpiece comfortably
receives the operator's thumb (not shown) and enhances the gripping of the handle and the manipulating of the knife.  While not shown, additional grooves of the same construction can be provided on the outer periphery of the boss 218 to allow the
thumbpiece 208 to be moved to a location on the opposite side of the centerface of the knife for left handed use.  The thumbpiece 208 positions the operator's thumb outwardly from the handle centerline, thus providing greater leverage to be applied by
the thumb to the blade.  Through adjustment of the thumbpiece position about the longitudinal axis of the base portion 230, the leverage provided by the thumb may be advantageously directed relative to, the direction of force to be applied during
cutting.


As can be seen in FIG. 3, when the thumbpiece is viewed from the side, the thumb support portion 232 has a proximal end 244 and a distal end 246 and is generally triangular in shape, with the longest leg of the triangle being the thumb contacting
surface 242 the thumb contacting surface 242 extends along a longitudinal axis P--P. The thumb contacting surface 242 is patterned with grooves to reduce the likelihood of thumb slippage during use.  The length of the thumb contacting surface 242 is
sufficient to provide support along substantially the entire length of the operator's thumb (not shown).  The profile of the thumb contacting surface 242 is generally sinusoidal in shape along its length.  As can be seen in longitudinal cross section in
FIG. 3, the sinusoidal thumb contacting surface has a concave middle portion 260 surrounded by proximal and distal convex portions 262, 264.  The proximal convex surface portion 262 is adjacent the thumb support portion proximal end 244 while the distal
convex surface is adjacent the thumb support portion distal end 246.  The contoured profile of the thumb contacting surface is ergonomically designed to allow the operator's first and second thumb joints to be somewhat flexed during operation of the
knife for maximum operator comfort and reduced fatigue.  In transverse cross section, that is, perpendicular to the longitudinal axis P--P, the thumb contacting surface 242 is concave or inwardly dished, thereby providing lateral support to the
operator's thumb and further reducing the likelihood of thumb slippage.


The thumb contacting surface 242 extends outwardly from the proximal end 244 of the thumb support portion along longitudinal axis P--P at an acute angle B with respect to the central longitudinal axis A--A of base portion 230.  In the preferred
embodiment, the angle of B is between 25 and 30 degrees and most preferably is about 27 degrees.  This angle maintains operator's thumb enough outwardly of the index finger to avoid lateral pinch.  The proximal end 244 of the thumb support portion 232
extends beyond the base portion proximal and 236, while the distal end 246 of the thumb support portion 232 extends beyond the distal end 248 of the base portion.


Cavities 250 and 252 near the interface of the base portion 230 and the thumb support portion 232 provide clearance between the thumbpiece 208 and the handle end 238 and between the thumbpiece 208 and the boss shoulder 220 respectively when the
knife 200 is assembled.


While the invention has been described with particularity with respect to preferred constructions, it will be apparent that various modifications and alterations can be made therein without departing from the spirit and scope of the invention as
set forth in the appended claims.


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